[hpoussin] 65127: [FREELDR] Move down the requirement of highest usable address This fixes PXE boot in QEMU, where highest usable address is 0x9c400.

Author: hpoussin
Date: Thu Oct 30 20:22:57 2014
New Revision: 65127

URL: http://svn.reactos.org/svn/reactos?rev=65127&view=rev
Log:
[FREELDR] Move down the requirement of highest usable address

This fixes PXE boot in QEMU, where highest usable address is 0x9c400.

Modified:
    trunk/reactos/boot/freeldr/freeldr/include/arch/pc/x86common.h

Modified: trunk/reactos/boot/freeldr/freeldr/include/arch/pc/x86common.h
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/boot/freeldr/freeldr/inclu…
==============================================================================
--- trunk/reactos/boot/freeldr/freeldr/include/arch/pc/x86common.h	[iso-8859-1]
(original)
+++ trunk/reactos/boot/freeldr/freeldr/include/arch/pc/x86common.h	[iso-8859-1] Thu Oct 30
20:22:57 2014
@@ -17,14 +17,14 @@
 #define FREELDR_BASE        HEX(F800)
 #define FREELDR_PE_BASE    HEX(10000)
 #define DISKREADBUFFER     HEX(8E000) /* Buffer to store data read in from the disk via
the BIOS */
-#define MEMORY_MARGIN      HEX(9E000) /* Highest usable address */
+#define MEMORY_MARGIN      HEX(9C000) /* Highest usable address */
 /* 9F000- 9FFFF is reserved for the EBDA */
-#define DISKREADBUFFER_SIZE HEX(10000)
 
 #define BIOSCALLBUFSEGMENT (BIOSCALLBUFFER/16) /* Buffer to store temporary data for any
Int386() call */
 #define BIOSCALLBUFOFFSET   HEX(0000) /* Buffer to store temporary data for any Int386()
call */
 #define BIOSCALLBUFSIZE     PAGE_SIZE /* max is sizeof(VESA_SVGA_INFO) = 512 */
 #define MAX_FREELDR_PE_SIZE (DISKREADBUFFER - FREELDR_PE_BASE)
+#define DISKREADBUFFER_SIZE (MEMORY_MARGIN - DISKREADBUFFER)
 
 /* These addresses specify the realmode "BSS section" layout */
 #define BSS_RealModeEntry        (BSS_START +  0)